Field of the Invention
The invention relates to compositions containing Bacillus sp., optionally with magnetite, useful in methods for collecting algae. The invention also relates to methods for collecting algae by contacting algae and bare maghemite and compositions thereof.
Background Art
Algal derived biofuels are one of the best alternatives for economically replacing liquid fossil fuels with a fungible renewable energy source. Algae can accumulate more than 50% of their biomass in oil and can be grown in saline water on land not suitable for agriculture. These characteristics mean algal biofuels do not compete for fresh water and arable land with conventional food crops. In addition, less land will be needed to produce the needed fuel than is required for other biofuel feed stocks. One major problem with algal biofuels is the algae most suited for biofuel production are small in size and difficult to harvest. Efficient harvest is crucial because algae cultures yield a few grams of algae per liter of water. The algae must be separated from the water before the oil can be extracted. At the laboratory scale algae cultures can be harvested by centrifugation or filtration, but these methods are too energy and capital intensive for harvesting algae from the immense volumes of water needed for commercial scale production of algal biofuels. Chemical flocculation can be used at large scales, but requires treatment of the water after the algae are removed so the water can safely be reused or released into the environment.
There is a need for improved methods for collecting algae.